That isn't much of an issue unless the river is extremely small. The huge amount of water traveling on most rivers with nuclear plants is orders of magnitude more than what's used in to do the heat transfer in the reactor.
Are you sure about this ? Not heat is produced ?
Cold fusion has been controversial in the 80's (https://en.wikipedia.org/wiki/Cold_fusion) and never really escape the lab.
They're likely referring to p+B11 fusion which is a potentially viable reaction that emits all its energy as accelerated charged particles (a current), which can, in theory, be slowed down by inducing a current in a coil (direct conversion). This skips the thermal cycle of electricity generation. There would still be heat, but it would be contained to the plasma with some amount of leak/waste.
There are a great number of asterisks on this. We are not close to making a p+B11 reactor.
Interesting. But I suspect it would take quite some time to get something like that in production. Nonetheless, we should keep do research, it could be the next generation of fusion reactors.
